This invention relates to construction machinery or a utility vehicle with at least one vehicle cabin or at least one driver's cab with a first seat with first control devices for a first operator, from which all of the essential driving and/or work functions of the construction machinery or of the utility vehicle can be controlled. At least one second seat with second control devices for a second operator is provided in the vehicle cabin/the driver's cab, from which all of the essential driving and/or operating functions of the construction machinery or of the utility vehicle can likewise be controlled, including a steering function for the vehicle. Control elements are provided by means of which a higher standing is assigned to the second control devices when the first and second control devices are simultaneously actuated, so that the second control devices override the first control devices.
So-called driving school vehicles in which control devices are provided for a second person, especially a driving instructor who sits on a seat next to the driver to be trained as a rule and who can intervene in events via his control devices when necessary, are known from the prior art; the second control devices have a higher standing vis-a-vis the first control devices of the driver, so the function carried out by the driver is overridden when the driving instructor intervenes. Only limited functions are usually provided for the second person in training vehicles of that type, though; they are the gas pedal, brake or clutch as a rule. The driving instructor cannot carry out a steering function, however. In the case of construction machinery, however, training according to the prior art up to now has either taken place via a second person in the driver's cab, who cannot directly intervene in events but only gives instructions, or the second person is even outside of the driver's cab, because there is not enough space in it for the second person.
DE 20 2007 003 703 U1 describes a military driving school vehicle in the form of a driving school tank with a driver's area and a driving instructor's area; a second steering mechanism that is coupled to a first steering mechanism via a cable and a magnetic return spring and that can override it in this way is assigned to the latter. Furthermore, the driving instructor's area has a second brake pedal that acts upon a hydraulic circuit via an application valve and that can act upon the first brake pedal of the driver's area via mechanical connection elements and override it from the driving instructor's area. This known vehicle does not involve a work vehicle, however, in which a dipper arm or extension arm has to be operated, for example. The above-mentioned document therefore does not offer a solution for overriding control elements for actuating a dipper arm or extension arm, for which so-called joysticks are used as a rule.
DE 10 2006 032 781 A1 relates to an arrangement for operating an actuator unit provided to guide a vehicle by means of an operating unit on the driver's side and an operating unit on the passenger's side in which control signals are generated that are transmitted to a control unit. The operating unit on the driver's side and on the passenger's side can be a steering wheel module, a brake pedal unit, a gas pedal unit or a clutch pedal unit here. This known arrangement is consequently only intended to be used for the above-mentioned control elements of motor vehicles and is used in driving school vehicles in the form of passenger cars. There are also no suggestions in this document for solutions as to how construction machinery can be equipped with two driver's areas from which all of the control functions of the construction machinery can be carried out in each case.
The Spanish patent specification ES 2 147 117 A1 describes trucks with two driver's areas next to one another that both have their own steering wheel and their own gas, brake and clutch pedals. Steering, acceleration and braking devices of the vehicle can be operated from both driver's areas via mechanical coupling elements. Only the gear shift and display instruments are arranged in the area of a central console between the two driver's areas. This vehicle also involves a customary driving school vehicle in the area of trucks. There are no provisions for the operation of work functions of the vehicle via joysticks.
DE 201 17 325 U1 describes a control device for use in a driving school vehicle that is driven by a learner driver; the control device controls functions or devices of the driving school vehicle. A driving instructor's stand that can be located in a second vehicle has a wireless module so that the driving school vehicle can be remotely controlled via a transmitter and receiver. Functions of the driving school vehicle such as the brake pedal, the gas pedal, the clutch pedal and the blinkers can be remotely controlled in a wireless fashion. The driving school vehicle also involves a motor vehicle for road traffic here, especially a bus.
In the case of earthwork machinery, multi-function operating controls that can be moved by hand are generally used as control elements (so-called joysticks); there are usually two joysticks of this type that are operated with the right hand or the left hand, and all of the basic functions of the vehicle are controlled by means of them, especially the advance, the back drive, the rotation of the vehicle around a standing chain, the rotation of the uppercarriage, the extension and retraction of the arm cylinder, the lowering and lifting of the extension arm, the tipping and dumping of the dipper etc. In the process, there can be functions that are only operated with one joystick and those that are controlled via the simultaneous operation of both of the joysticks. Multi-function operating controls (joysticks) of this type can both be tilted forwards or backwards and to either side starting from an upright position, so at least four different functions can be controlled by the operation of a joystick alone.